Radiotelegraphy



F. S. McCULLOUGH.

RADIOTELEGRAPHY.

.APPLICA-ION .FILVED AUG 2. 191 s. 1,427,833, PatentedSept. 5, 1922.

g I I T 8/ F. S. McCULLOUGH.

RADIOTELEGRAPHL I APPLICAIION FILED AUG12.|I91.9-

PatentedSept. 5, 1922.

2 SHEETS-SHEET Z.

Erma/ ms;

Patented Sept. 19:22.

UNITED STATES.

meat-33 PATENT OFFICE.

FBEDEBIGK S. MOOULLOUGE, OI CLEVELANI OHIO, LSSIGNOB TOGWH Ia. MARTIN,

OI CLEVELAND, OHIO.

mrornnmmirr.

Application filed August 2, 1019. Serial No. 314,954.

To all whom it may concern;

Be it known that I, FREDERICK S. MCCUIL-I tant transmitting stations. It also relates to systems for detecting the incoming electroma netic waves.

- In t e radio directional systems hithertoused, .there have been employed large antennae arranged in certain shapes anddirections, and also loops or coils of wire, these .coils generally havin a number of'turns wound on a square rame with the sides several feet or several yardsfin length. 26 While directional loo s of such size may an-'- swer for permanent and stations, it can be readily seen'that there are grave objections to them forportable stations: such as'those on aismall boat,tand more particularly on .80 aircraft. For the latter it is essential to have the apparatus mas compact form-as possible, and b my system I rovide means ofosmall size w 1ch will satis ac'torily determine the direction of transmitting radio sta- 85 tions. Together with my direction, finding,

I provide for the detection of the incoming electrical oscillations.

The annexeddrawings and the following descri tion set forth in detail certain means embo ying ,my invention, the disclosed means, however, constituting but one of the various mechanical forms-in which the princi 1e of the invention ma be em loyed.

n the drawings, which are argely diaammatic, Figure 1 shows one form of my invention, with one 10f the elements shown in cross-section, the sectionbeing taken on the line CD, in Figure 2.

Figure 2 is a view, partly in section, show-' ing some of the elements of my system, the

flat coil in the form of a circular spiral.

being taken on the line A'B-,

. conductor. of my ,a conducting ribbon wound in'a Figure 2 shows a section of the ribbon flat spiral coil, on an end scale. igure 3 is a modified form of m system, with means for indicating visual y the received signals.

Figure 4 is another modification of my system, with other means for indicatingvisually the strength of the received signals.

Figure 5 shows another modification of my system.

Figure 6 shows another modification of lar my system with the fiat spiral coil enclosed in an evacuated tube.

InFl re 1, 1 is a vacuum bulb or tube; 2 is a fi ament which may be heated; 3 is a plate of conducting material which is here shown disc-shaped, but may have an other suitable shape; 4 is a battery for eating filament '2, and '5 is a variable resistance for regulating the current therein; 6 is a battery for energizing the circuit containing the plate 3,the filament 2 and an indicating means 7 which is here shown as a telephone, but may be any other suitable iridicatin means; 8 is a section ofa flat coil made 0 v sguare spiral with the ad acent turns placed e ge to ed e.

-9 is a'varia le inductance and 10 a va'ria 1e condenser in the circuit connecting the flat coil '8 and the filament 2. 11 is 'a' r1n to which the coil 8 is secured, and whlch s ips over the tube 1, along which it may move.

Suitable flexible donnection's with coil 8, or sliding contacts, are provided to its 'motion;- This ring 11 is pre erably of conducting material, in which case the inner ermit of.

turn of the spiral-8 is electrically connected with it.

In Figure 2, which is a section taken on the line A-B, looking in the direction of the arrow, 1 is the vacuum tube; 2 is a cross- -section of..a filament; 3. is an end view of flat coil wound in the form of a circular- I spiral. 41, 41, are blocks or pieces of insulating material for keeping the turns of the spiral separated from each other.

In Figure 2, the section of theribbon conductor of my flat spiral coil is shown on an enlarged scale. In some embodiments of my invention I have made this ribbon about .005 inch thick, and about or inch wide, but I do not confine myself to these sizes and proportions. I may also make my coil of as many turns as found most suitable for a given case... In these ways I can vary the capacitance and inductance of my coils, to suit the wave lengths and other conditions of any case. In order to get the greatest directive efl'ect in the coil, it is advisable to have the greater part of the inductance and capacitance of its circuit in the coil itself.

In Fi re 3, 2 is a. filament which may be heate by current from the battery 4, 5 being a variable resistance for regulating the current in the filament. 8 is a flat iral coil similar to the one already describe 11 is a ring or band fitting on the vacuum tube 13, along which it may move. Suitable flexible connections or sliding contacts are provided,'to permit of this motion. 14 is a small fiat spiral coil of a few turns contained within the tube 13 and electrically connected with the flat spiral coil 8, as.

shown. Coil 14 is also connected to the filament 2 through the variable inductance 9 and variable condenser 10. 15 is a flat coil in the form of a circular iral havin more turns. than has coil 14. oil 15 vis a so located within the tube 13 and is connected with the fiat coil 8 through the variable inductance 16 and variable condenser 17 It is also connected with a cathode-ray tube 18 which serves as a visual indicator. 19 is an induction or spark coil; 20 is an anode and 21, a cathode within the cathode-ray tube and connected to the terminals of the spark coil. 22 is a diaphragm in the cathode-ray tube, having a small openin which permits a beam or pencil of oath e rays to pass through. 23 and 24 are electrodes in the cathode-ra tube and connected with the circuit which also includes plate 15, the filament 2 and the battery 6. 25 and 26' are positions assumed by the beam of cathode rays when under the influence of the electrodes 23 and 24. 27 is a screen, which ma be of mica or some other suitable. materia On which the beam of cathode rays impinges making a spot of light when the beam isat rest and a line of light when it 15 in rapid motion.

In Figure 4, 13 is a vacuum tube; 28 is a filament contained in the tube which can be heated by the battery 4, the current in this local circuit being regulated by the variable; resistance 5. 30 is a coil-in the tube ia'nd-r here shown extending nearly through-' on :jshe length of the tube but this coil may have any suitable length. This coil 30 is connected with the filament 28 through the variable inductance 9 and variable condenser 10. Coil 30 is also connected with another coil 31 wound outside of the tube 13 on a ring 'or band 32 which fits over the tube and can'be moved along it. A cylindrical covering, 43, ma surround coil 31. Coil 31 is also connected with the fiat spiral coil 8, which is similar to the coils 8 shown in the previous figures. Coil 8 is attached to a ring 33 which fits over'the coil 31 and is movable along the latter and also along the tube 13. Suitable flexible connections or sliding contacts are made with coils 31 and 8, in order to permit of their motion. 29 is another coil contained within the tube 13 and woundoutside the coil 30, and here shown extending nearly throughout the length of the tube, but this coil may have any suitable length. Coil 29 is connected with coil 8 throu h the variable inductance 16 and the variab e condenser 17, and is also connected with the filament 28. In the latter circuit are included the battery 6 and the galv-anometer 34. The galvanometer 34, which may be of any suitable kind, serves to indicate visually the strength of the signals received by the system, but insead of a galvanometer there may be used any other suitable visual indicator, or any other suitable means for indicating or recording signals. In Figure 5, 35 is a vacuum tube; 28 is a filament contained therein, this filament bemg heated by a battery 4, and the current therethrough being regulated by the variable resistance 5. 29 is a coil within the tube 35, and here shown extending nearly throughout the length thereof, but it may have another suitable length; 36 is a coil wound outside the tube, and preferably extendinglthe length thereof, but it may have any 0t ersuitable length. It is movable w th respect to the tube 35, and is connected with the coil 29 through the variable condenser 17 and with the filament 28 through the variable inductance 9 and variablecondenser 10. Suitable flexible connections or sliding contacts are provided to permit of such motion. The coil 29 is connected with the filament 28," the circuit including also the variable battery 6 and the indicating means 7, which is here shown as a telephone, but which may be any other suitable indicatlIl means, either audible or visual.

nfF gure 6, 37 is an evacuated tube, which is shaped so as to contain the flat spiral coil 8. 28 is a filament; 29 is a coil, preferably extendin through the greater partof the len h o the tube; 30 is another coil between the filament and coil 29, and

also preferabl extending through most of the tube. Coi 30 is connected with one end of the flat spiral coil within the tube. 4 is a battery for heating the filament 28, and

isa variable resistance for regulating the stren able inductance and a variable condenser betweenthe coil30 and filament 28. 16 is a variable inductance and 17 a variable condenser between the coil 29 and the flat spiral coil 8. 6 is a variable battery for energiz- Y ing the circuit comprising coil 29, filament visually or audibly may be 28 and galvanometer 34. Galvanometer 34 may be of any suitable kind, andwill indicate visually the stren th of, the received signals, but instead 0 the galvanometer, any other means for indicati ig these signals used. The fiat spiral coil 8 may be attached to a ring or frame 39, and supported in the tube by the.

wiresor rods 38, 38, and 40, butany other suitable means ofsupporting and se- (:lll'lIlF spira may be either circular, square orrectangul arin shape, 'as found most oonvement. Y

The flat spiral coils which have been de: scribed above ar referably composed of a thin ribbon shaped conductor, the cross-sectlon of which is rectangular ,or oblong in shape. They may have any convenient number of turns and their dimensions-over enclosed n an evacuatedtube, it will be con- .the coil less thana coil with 'the fribbon-shaped conductor is sharply directive and enables me to provide a sensitive and eflicient direction finder in a small and compact form. The; square all ma be a foot or less, althou' h in'some ,cases t ey may belarger' than t is. When venient to have the greatest dimension of oot. This flat spiral shape has mechanical advantages in construction and support, but a circular sha 0 may also be used. ere necessary it ,e turns of the coil may be kept separated by means of pieces of insulating material. and where advisable an insulated framework may be employed to support? the coil and' preserveits sha e. In onernethod of construction I win my spiral on a flat surface,

then' dip it in an ins ulating enamel bath,

- heat it in an oven, and their place it be tween two sheets or blocks ofinsulating ma- .terial, such as 'bakelite. In this way the turnsof the spiral are insulated .from each other, the spiral is insulated fromlo'utside conductors, and the. spiral is supportedand its shape reserved. Inthis way it is-a'lso protected om dampness corrosion pr other atmospheric influences. W

of'the'tube, the coil may be moved along I to the tube ,into the position found most-advanta eous.

i In t e arran ment shown in Fi re 1,- it

has been foun that'the best os1tion for coil 8 is that in which its plane es between the end of filament 2 and plate 3. In this positibiiit is robable" that its field will be strongest in t e space between the filament h of the current therein. 9 is a vari-.

this coil may be employed. This flat hen used outside erably 'be in the same plane with coil" I '8 and both these coils and coil 15 should be parallel to each, other. These coils should also preferabl the same sense. In t is arrangement the rincipal directional efi'ect is probably no to coil 8, although coils 14 and 15 all be wound in y will assist. The detecting -function with this arrangement is largely due to the combined action within the tube of filament 2 and coils 14 and 15, assisted to some extent by coil 8' and by the other apparatus outnals is indicated by the aid of a cathodera tube 18, the action of which has-been fu ly explained in my coending application Serial No. 313,161, file July 2, 1919. It will be sufficient to say here that the-variations in the'electrification of the electrodes 23 and 24, due to the incoming electromagnetic waves, as modified by the receiving apparatus, cause the beam of cathode rays side of the tube. The strength of the sig- 25 and 126 to move from its normal position and to trace a line of ii ht on the screen 27. 'The length. ofjthis ine will indicate the strength of the received si nals. I

In the arrangement shown in, i "re 4, the

directional effect is obtained b al the coils, those outside.

both those inside the'tube an the tube. These coils should'pref erably be parallel, to each other and'all wound in the same sense. vThe'inductance of the system 1 may be varied by the coil 31, which can slide outside of the tube. The wave-detecting function is largel ,due to the filament and coils within the tu In this figure the galvanometer is shown as the'means for indi- .cating the strength of the received signals,

This move spark or group frequency of the transmitt1ng station, but. itmay be of any other suitable kind, andinstead of a go. vanom- ;ete'r, I mayemploy a cathode-ray tube or 1 anymther suitable visual or, audible'means s1 alsp'.

f indicating, thestrength of. the received.

n the-arran em'ent shown in Fi re 5 galva'nometermay have a reed or other y le 'part'whlch can be tuned to the the directive e ect is secured bybot coils; and the detectin effect i's'partly due to the field created in t e space within the tube by the coil 36, which is wound outsideof the tube and closely adjacentthereto. The inductance of the system can. be varied by slidingcoil- 36 along'the tube.

In the arran ement shown in Figure -6,; the directive 'e ect is secured by the action .ting station-or stations.

of'all the coils, which should be parallel to each other and which should preferably be wound in the same sense. The detecting function is performed by the combined action of all the elements within the tube, and is probably principally due to the filament 28 and coils'30 and 29. The fiat spiral coil 8 may, be supported as shown, or where advisable, it may have an insulated framework to help support it and preserve its shape and to keep adjacent turns from touching, or it may be held between two point toward the transmitting station.-

VVhere my coils do not liein a plane, as for instance, when they are wound in helical form, the direction is the average direction of the individual turns, or, more exactly, the direction perpendicular to the axis of the coil. Sometimes'it is more convenient to determine the position for minimum effect, which is at right angles to the position for maximum effect.

I may combine different units of my system so as to indicate simultaneously the positions for maximum and minimum effect of the received signals. I may also employ these units so as to show simultaneously the direction of two or more distant transmitting stations. I- may also combine different elements so as to secure amplifying efl'ects for the received radiant energy.

In the system shown in this application, and in all other modifications coming within the scope of my invention, I may tune my c rcuits to the wave length of the transmitting station or stations; and other parts of my'receiving apparatus such, for instance, as the galvanometer, may be tuned to the spark'or group frequency of the transmit- In this manner I can secure highly selective efi'ects.

In all the embodimentsof my system. the

size or dimensions and forms of my elements and the electrical quantities involved are so chosen as to secure the best results in each case. In general, I do not limit myself to the exact. constructions and arrangements shown in this specification, but any suitable means coming within the scope of my invention may be employed. D

What I claim and desire to secure byLetters Patent is:

1. In a radio system, in combination, a vacuum tube, a. filament and a plurality of coils contained therein, and a coil surrounding said tube, the axes of. all said coils being parallel to each other, said coils being connected conductively.

2. In a, radio system, in combination, a vacuum tube containing a filament and a plurality of coils, anda flat spiral coil about said -tube having its plane perpendicular to the axes of said coils within the tube, said coils being connected conductively.

3. In a radio system, a receiving circuit comprising a vacuum tube, a filament, a plate element within said tube, and a directiraal receiving element surrounding said tu i 4. In a radio system, in combination, a vacuum tube containing a filament and a plate, and a fiat spiral coil surrounding said tube, havin its axis of sai tube.

5. In a radio system, in combination, a vacuum tube, a fi to each other and together with the lament being contained in said tube, and a ribbon: shaped conductor wound in a flat spiral'oub.

plane perpendicular to the ament, a coil of wire, a second c011 of wire, said coils being arallel side of the tube and adjacent thereto, and. I

with its plane parallel to said'coils inside the tube.

6. In a radio system, the combination ofv a vacuum tube, a filament, a plate member," and a'third member comprising a coil within said tube, a coil outside said tube and partly surrounding the tube, and a flat spiral coil outside said tube, sald three col-ls beingI connected conductively.

n a radio s stem, in combina'tiomiavacuum tube, a 'fi ament, coils within said tube, and movable COIlS SllIlOllIldlIlg said tube, said c'oils being connected conductively.

Signed b me, this 29th da of Jul ,1919. FRE ERICK S. Mo ULLO GH; 

